Fibrinogen plays key roles in both blood clotting and platelet aggregation. During blood clot formation, the conversion of soluble fibrinogen to insoluble fibrin is triggered by thrombin, resulting in the polymerisation of fibrin, which forms a soft clot; this is then converted to a hard clot by factor XIIIA, which cross-links fibrin molecules. Platelet aggregation involves the binding of the … expand

Fibrinogen plays key roles in both blood clotting and platelet aggregation. During blood clot formation, the conversion of soluble fibrinogen to insoluble fibrin is triggered by thrombin, resulting in the polymerisation of fibrin, which forms a soft clot; this is then converted to a hard clot by factor XIIIA, which cross-links fibrin molecules. Platelet aggregation involves the binding of the platelet protein receptor integrin α(IIb)-β(3) to the C-terminal D domain of fibrinogen [ PUBMED:12799374 ]. In addition to platelet aggregation, platelet-fibrinogen interaction mediates both adhesion and fibrin clot retraction.

This entry represents the coiled-coil domain and part of the N-terminal E domain found in all three fibrinogen polypeptides, namely the alpha, beta and gamma chains.